Visual Regression Testing

Implement visual regression tests to catch unintended theme changes:

• Screenshot comparison across theme variations
• Component state testing
• Responsive breakpoint testing
• Color mode transition testing

Accessibility Testing

Ensure your theme meets accessibility standards:

• Color contrast ratios
• Focus state visibility
• Text readability
• Interactive element sizing

Cross-Browser Testing

Test theme consistency across different browsers:

• CSS variable support
• Font rendering
• Color mode implementation
• Animation performance

How do I maintain consistency across different components?

Use a design token system with CSS variables to maintain consistency:

:root {
  /* Base tokens */
  --color-blue-500: #3b82f6;
  --spacing-4: 1rem;
  
  /* Semantic tokens */
  --color-primary: var(--color-blue-500);
  --button-padding: var(--spacing-4);
}

How can I test my theme across different devices?

Implement a comprehensive testing strategy:

• Use browser developer tools for device emulation
• Test on physical devices when possible
• Implement responsive breakpoints using CSS variables
• Use automated testing tools for cross-device verification

Should I use CSS-in-JS or CSS variables for theming?

Both approaches have their merits:

• CSS Variables: Better performance, native browser support, easier debugging
• CSS-in-JS: Type safety, dynamic theming, component co-location

Choose based on your project needs, team expertise, and performance requirements.

How do I handle theme switching?

Implement theme switching using CSS classes or data attributes:

/* Theme switching with data attributes */
[data-theme="light"] {
  --background: white;
  --text: black;
}

[data-theme="dark"] {
  --background: #1a1a1a;
  --text: white;
}

/* Theme switching with classes */
.theme-light {
  --background: white;
  --text: black;
}

.theme-dark {
  --background: #1a1a1a;
  --text: white;
}